Kinetics and mechanism of base hydrolysis of (dimethyl sulphoxide)penta-amminecobalt(III) ions

Scientific paper - Original scientific paper

• Author: M. Biruš
• Author: W. L. Reynolds
• Author: M. Pribanić; MBZ: 38805
• Author: S . Ašperger
• Author's institution: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of physical chemistry)
• Author's institution: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of general and inorganic chemistry)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry

Abstract (english)

Data are presented showing that at constant 0.02 M OH- the
rate of the base hydrolysis of the (NH3)5 Co(DMS0)3+ ion increases
with an ·increase in the nonaqueous component in aqueous-organic
mixtures containing methanol, ethanol, DMSO ( = dimethyl suiphoxide),
acetone or dioxane. The enhancement in the rate, which
amounts to more than 100 fold in organic component-rich mixtures,
is discussed in terms of an increase of the basicity of the mixed
solvents due to the decreasing salvation of OH-. The base hydrolysis
of the DMSO-complex ion in the presence of 1 M anion Y and
0.125 M Off yields 12.8, 9.9, 7.8, 1.8, and 3.7 mol 0/o (NHs); CoY from
(NH3); CoX for the competing anions Ns-, ScN-, N02-, OAc-, and
S04 2-, respectively. The mechanistic implications of these results are
discussed in terms of SNlCB and Id mechanisms.

• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Croatica Chemica Acta
• Numbering: vol. 47, no. 4, pp. 561-568
• p-ISSN: 0011-1643
• e-ISSN: 1334-417X
• URN:NBN: urn:nbn:hr:163:327958
• Publication: 1975
• Document URL: https://hrcak.srce.hr/196576
• Type of resource: Text
• Access conditions: Open access
• Created on: 2020-05-05 15:45:51